Conventionally, substrate treating apparatus include a coating apparatus for coating substrates with a coating solution such as of photoresist. The coating apparatus has a holding and spinning unit for holding and spinning each substrate, a plurality of coating solution nozzles which dispense the coating solution, and a nozzle moving mechanism for moving the coating solution nozzles to arbitrary positions. The plurality of coating solution nozzles are held in standby pots provided laterally of the holding and spinning unit and in the same number as the coating solution nozzles (see Patent Publications 1-3, for example). The nozzle moving mechanism grips one of the coating solution nozzles standing by in the standby pots.
As shown in FIG. 10, each standby pot is capable of dummy dispensation, and includes a nozzle standby portion 131 for receiving a coating solution nozzle on standby, and a solvent suction portion 135 for a solvent to be sucked into a tip end of the coating solution nozzle. Where the coating apparatus has ten coating solution nozzles, as shown in FIG. 11, the standby pots are provided in an array of ten sets each including one nozzle standby portion 131 and one solvent suction portion 135.